One type of variable reluctance motor utilizes a rotor formed of axially spaced apart disks that are rotatable relative to a stator portion. The stator portion is stationary and also formed of disks located intermediate adjacent pairs of the rotor disks. A stator winding circumscribes each stator pole pair and, when energized, directs an electromagnetic field axially through a magnetic circuit formed of the energized stator pole pair and adjacent rotor poles. Torque is generated when a pair of rotor poles move toward a position of axial alignment relative to an adjacent energized stator pole pair to minimize the reluctance. Examples of this type of variable reluctance motor are disclosed in U.S. Pat. No. 3,700,944 to Heintz and U.S. Pat. No. 3,992,641 to Heinrich et al.
Another type of variable reluctance motor is formed of an elongated rotor mounted coaxially within an elongated annular stationary stator. Each of the rotor and stator has a plurality of radially protruding poles or teeth that extend axially. An annular air gap separates the rotor poles from the stator poles. The stator generates an electromagnetic field when a stator winding associated with a pair of opposed stator poles is energized. The electromagnetic field is directed radially with respect to a central axis extending longitudinally through the rotor and the stator. The electromagnetic field urges a pair of opposed rotor poles into radial alignment with the stator poles being energized to minimize the reluctance of the corresponding magnetic circuit formed by the energized stator poles and adjacent rotor poles. The movement of the rotor, in turn, generates torque. Examples of this type of variable reluctance machine are disclosed in U.S. Pat. No. 4,670,696 to Byrne et al. and U.S. Pat. No. 5,747,912 to Sakuma et al.